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Objective To develop an HPLC-MS/MS method with solid nuclear particle chromatographic column to determine 15 afrodyn drugs illegally added in sex-enhancing product. Methods The analysis was performed by an HPLC-MS/MS system, with Cortecs-C18 (150 mm × 4.6 mm, 2.7 μm) column. Multiple-reaction monitoring (MRM) was performed to identify and quantify phentolamine mesylate, noracetildenafil, acetildenafil, vardenafil, sildenafil, hydroxyhomosildenafil, homosildenafil, aminotadalafil, tadalafil, thioaildenafil, pseudovardenafil, norneosildenafil, methyltestosterone, stanozolol and danazol, which were extracted with methanol by ultrasonic. Results The linear calibration curves of 15 chemical components mentioned above were obtained at r2 ≥ 0.995 4 with better separation degree and wide linear range. The precision of the method was shown by RSD (n = 6) from six estimated values ranged from 0.9% to 3.3%. The recovery rates determined at three adding concentrations were from 88.3% to 109.5% and the RSD was from 0.9% to 5.2%. The range of limit of quantitation (LOQ) were from 0.015 μg/mL to 0.30 μg/mL and The RSD of inter-day and intra-day precision were from 0.9% to 4.2% and from 1.0% to 4.5%, respectively; Twenty batches of positive samples of 25 batches of sex-enhancing products were detected to be added with sildenafil and with an unqualified rate of 80%. Conclusion The method is specific and simple to detect that 15 afrodyn drugs were added illegally in sex-enhancing product. At the same time, the high positive detection rate should attract the attention of the department concerned, and the corresponding policies should be issued to guarantee the health and safety of the people.
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INTRODUCTION: Several cases of adulteration of dietary supplements with tadalafil, sildenafil, and vardenafil, or their unapproved analogues have been reported worldwide. Mainly, the presence of the latter represents a serious health risk to consumers as their efficacy and toxic effects have not been assessed and may result in unpredictable adverse effects. AIM: To investigate the suspected adulteration with synthetic phosphodiesterase type 5 (PDE-5) inhibitors in a dietary supplement marketed in Argentina for the treatment of erectile dysfunction (ED). METHODS: The content of the capsules of the dietary supplement (sample A) was analyzed by thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) diode-array detection. From the organic extract of sample A, a major compound was purified by column chromatography (CC). The isolated compound was identified by proton nuclear magnetic resonance (1H NMR) and carbon NMR (13C NMR), heteronuclear single quantum coherence, distortionless enhancement by polarization transfer (DEPT 135), electrospray ionization mass spectrometry, and ultraviolet, and infrared (Fourier transform infrared spectroscopy) spectroscopy. MAIN OUTCOME MEASURE: Proof of adulteration of herbal products with synthetic PDE-5 inhibitors. RESULTS: By TLC and HPLC analysis, a major compound was detected in sample A organic extract. The purification of this extract by CC led to the isolation of a pure compound which was identified according to its spectral data as (6R,12aR)-2-amino-6-(1,3-benzodioxol-5-yl)-2,3,6,7,12,12a-hexahydropyrazino [1',2':1,6] pyrido [3,4-b] indole-1,4-dione or aminotadalafil. CONCLUSIONS: An unapproved PDE-5 inhibitor analogue, which was identified as aminotadalafil, has been detected in a dietary supplement. This study represents the first report in Latin America and one of the few independent studies of an adulteration with an unapproved PDE-5 inhibitor of an herbal product for ED treatment.